Radio frequency identification (RFID) labels and tags are a common tool for labeling, identifying, and tracking various goods and people. The goods so labeled involve a wide range of industries and include packages being shipped, cars, keys, livestock, identification badges, and merchandise in stores. RFID tags, either active or passive, are typically used with an RFID reader to read information from the RFID tag embedded in the label. For passive tags, a typical RFID reader/writer energizes transponder circuitry in the tag by transmitting a power signal. The power signal may convey data, which can be stored in a transponder memory, or the transponder circuitry may transmit a response signal containing data previously stored in its memory. If the transponder circuitry transmits a response signal, the RFID reader/writer receives the response signal and interprets the stored data. The data is then transmitted to a host computer for processing.
Besides directly attaching a chip to an antenna, another current technique for manufacturing RFID chips for use in tags is using a strap assembly system. The strap assembly system includes inserting the RFID chip into an RFID “strap” where the chip is connected to two oversized contact pads. This technique allows for greater mass production of RFID components, as the chip with oversized contacts can be inserted into circuitry, for example connected to an antenna, with much greater ease. The RFID straps are typically mounted on a substrate while being manufactured, and may be mounted on a substrate in use as well.
In both direct attach and strap assembly RFID systems, mass production of the circuitry can lead to some variability in the resulting RFID tags. Sometimes this variability is only detected at the end without a suitable way to correct it. There is a need for a way to dynamically correct errors or variability in RFID systems production.